Using a sharp paring knife, slice each potato crosswise at 1/8-inch intervals, cutting down but not all the way through the potato. Transfer the potatoes to a baking sheet. Drizzle with 5 tablespoons of the pimentón oil, season with salt and pepper and toss to coat. Roast the potatoes cut sides up for 20 minutes. Insert one bay leaf into each potato and roast for about 20 minutes longer, until the potatoes are golden, crisp and cooked through. Transfer the potatoes to a platter, discard the bay leaves, drizzle with the remaining 1 tablespoon of pimentón oil and serve.